Today I tried setting both projectors to 50 Hz, and using movies with HAP Q Codec. The stuttering was still there, sometimes I thought even worse. I am really surprised that it is such a problem to play two 1080p25 movieswqithout stutters with Isadora?

I will try the normal HAP (with quality setting: best) and ProRes 422 tomorrow, but if this does not help I am really clueless. I tried changing the "General Service" setting but I do not quite understand if this has any impact on just video playing at all?

Are these video files you created from scratch (original motion graphics), original footage, stock video, or media you got from another source?

What application are you using to export or convert the video?

Different video codecs are compatible with the AVfoundation playback engine in Isadora. This mouseover information is to help you determine which playback engine and playback mode to use with your media in your movie players.

Which playback engine and optimization have you been using for your ProRes movie players?

Hap cannot be played with AV foundation in Isadora yet. But will be with the next release. And in any case you have the adobe creative cloud installed, please read this: https://support.troikatronix.c...